Ecumenical council

The Ecumenical council is a gathering of bishops to determine weightly religious matters. There have been seven such councils:

The Great & Holy Council of Nicea
The 2nd Great & Holy Council - Constantinople, 381 AD
The 3rd Great & Holy Council - Ephesus, 431
The 4th Great & Holy Council - Chalcedon, 451
The 5th Great & Holy Council - The 2nd Council of Constantinople, 553
The 6th Great & Holy Council - The 3rd Council of Constantinople, 680
The 7th Great & Holy Council - Nicea, Asia Minor, 787 A.D. - Affirmed the propriety of icons as genuine expressions of the Christian Faith.